Beat the HEAT; Gardening.

Byline: PIPPA GREENWOOD

We've already experienced some warm, dry stretches this year - and the forecasters predict more plantshrivelling weather to come.

So how can you prevent further damage - and what should you grow to ensure that your garden looks tip-top despite hot, dry conditions?

Sort sandy soil

Light, sandy soils are the most free-draining. So if it does rain, or you do water, all that much-needed moisture tends to drain away very rapidly, often before the plants can take full advantage of it.

So incorporate plenty of bulky organic matter such as garden compost, well-rotted manure plus the contents of old pots, planters and growing bags. This will make it easier for the soil to hang on to any available moisture for that bit longer.

Stop clay cracking

During hot, dry weather clay soils can start to crack. If deep cracks develop, drying air can get to the plants' roots, causing serious damage, and this is often made worse by the cracking soil actually ripping fine roots apart. Fork in bulky organic matter to help retain as much moisture as possible.

Make a miracle mulch

Applying a mulch - usually a 2-3in (5-8cm) layer of compost, proprietary mulch mix, composted bark or cocoa-shell - to the soil really helps keep the water where you want it and reduce evaporation.

Make sure the soil is thoroughly moist before applying the mulch, as mulching on dry soil may have the opposite effect and actually keep it dry! Don't be tempted to cover the soil with polythene to prevent it losing water - it's not good for the soil or the plants and also stops any rain or other water getting through to the plant roots.

Save and recycle

Install at least one water butt to collect water from house, greenhouse, shed or garage roofs. Fix a water diverter to the downpipe from the gutter to make collection easy.

It's also worth seeing if it's possible to put a diverter on the downpipe taking used water from your bath or shower - normal use of soap, shampoo and bubble-bath shouldn't cause problems to garden plants. If watering restrictions come into play, you'll be especially glad you've done it.

Pick your planting moment

Avoid putting new plants in the ground if it's very hot - evening plantings are usually best as once they're watered in, the new plants will have the rest of the evening, night and early morning to settle in before being subjected to the heat of the day.

A temporary covering to create some shade for the first few days after planting will also help to reduce the stress they suffer - even newspaper will help.

Dig a pit

When you plant, make a slight depression in the soil so any water that hits the surface will roll down and into the depression around the plant's roots. Before the plant goes into the ground, drench the base and sides of the planting hole with plenty of water. Plant as usual, then water the plant in and top off the soil surface with a little dry soil followed by a mulch (see above).

Watch out for walls

The area close to a wall which has foundations tends to be especially dry. Once the sun heats up, the soil gets even drier and the wall itself acts a bit like a storage heater, giving off heat.

This can spell disaster for plants, especially in a naturally hot, dry site. In these areas, always dig a massive planting pit, incorporating lots of organic matter, and plant as far away from the wall as practicable.

Great plants for dry sites

Look out for plants with slightly furry foliage (this often looks grey or silvery in colour) and plants with fleshier leaves. Both adapt well to dry or drought-prone situations. Good choices include:

Achillea

Armeria (thrifts)

Aubrieta

Cistus (rock roses)

Dianthus (sweet William)

Eschscholzia (Californian poppy)

Genista (brooms)

Helianthemum (sun roses)

Helianthus (sunflowers)

Juniperus (juniper),

Rosmarinus (rosemary)

Sedum (ice plants)

Sempervivum (house leeks)

Stachys lanata (lambs' ears)

Thymus (thymes)

Clever idea

If temperatures in your garden frame or greenhouse are soaring, reduce the amount of sun getting in. Ideally, paint the glass with a proprietary greenhouseglazing paint. If you can't get hold of any, use watereddown emulsion paint instead. You can take the paint off when light levels start to fall later in the year.

Help!

Why are some of my pot plants looking thirsty when they've been recently watered? The leaves are the normal colour but a bit wilted.

M J Lawson, N Hampshire Pippa says: I'm sure they are probably in need of more water at the roots. The weather over the past weeks has been quite warm and therefore very drying. But a bigger factor could be wind. In many cases windy conditions are actually more drying to plants than warm spells - I suppose it's a bit like hanging wet laundry on the washing line on a cool but windy day! Check the feel of the compost in the pots a couple of centimetres below the surface and water and mulch as necessary.

PIPPA GREENWOOD has presented her own series, Growing Science, on Radio 4 for three years and is a regular panelist on the station's Gardeners' Question Time. She's also written many books including Pippa Greenwood's Gardening Year (Headline, pounds 16.99).

CAPTION(S):

TOUGH: Rock roses, thyme HOT CHOICE: Dianthus (Sweet William) BASKING IN IT: Eschscholzia (Californian poppy)